Today, a huge amount of personal cards is in practical use, with an increasing focus on applications requiring higher security. RFID technology was implemented as a comfortable interface for the user and world-wide standardized about one decade ago in the ISO/IEC14443 Proximity Standard. This standard, as well as all other standards in the field of RFID are considered to be well-known to the person skilled in the art. RFID technology enabled electronic passports, contactless credit cards (E-banking), access control or public transport ticketing as successful solutions being part of our daily life. The typical format of such cards is ID-1, specified in the ISO/IEC7810 standard.
A new trend is visible wherein RFID technology is being used for payment applications. In such applications contactless stickers with ISO/IEC14443 smartcard transponder chips are sticked to mobile phones, for example. Mobile Phones may have cases made of plastic, containing metal parts, or consist of metal, and may have different sizes. A typical transponder card attached to a metal plate will not operate properly, because the magnetic flux passing through the antenna coil will produce eddy currents in the metal, and these will produce an opposite H-field, which practically cancels out completely the Reader field. Thus, the contactless transponder gets no energy for operation. A ferrite foil in-between transponder loop antenna and metal case will allow a part of the magnetic flux to pass through the foil, and not contribute to the eddy currents. The result is that some H-field remains to power the transponder and allow (limited) operation. Such contactless systems operate with resonance to increase induced voltage. The antenna design must meet the criterion that resonance frequency is close to the operating carrier frequency, to have most energy. Loop antennas with ferrite will be detuned in different way by the presence of metal or plastic (˜3 MHz for a practical case).
Another application of RFID technology is the replacement of UPC or EAN barcodes with RFID tags. RFID technology has a number of important advantages over the older barcode technology. They may not ever completely replace barcodes, due in part to their higher cost and the advantage of multiple data sources on the same object. The new electronic product code (EPC), along with several other schemes, is widely available at reasonable cost. The storage of data associated with tracking items requires many Terabytes. Filtering and categorizing RFID data is needed to create useful information. It is likely that goods will be tracked by the pallet using RFID tags, and at package level with Universal Product Code (UPC) or EAN from unique barcodes.
The unique identity is a mandatory requirement for RFID tags, despite special choice of the numbering scheme. RFID tag data capacity is large enough that each individual tag will have a unique code, while current bar codes are limited to a single type code for a particular product. The uniqueness of RFID tags means that a product may be tracked as it moves from location to location, finally ending up in the consumer's hands. This may help to combat theft and other forms of product loss. The tracing of products is an important feature that gets well supported with RFID tags containing a unique identity of the tag and also the serial number of the object. This may help companies to cope with quality deficiencies and resulting recall campaigns, but also contributes to concern about tracking and profiling of consumers after the sale.
It has also been proposed to use RFID for point-of-sale (POS) store checkout to replace the cashier with an automatic system which needs no barcode scanning. In the past this was not possible due to the higher cost of tags and existing POS process technologies. However, Industry Standard, a couture shop and recording studio in Ohio has successfully implemented a POS procedure that allows faster transaction throughput.
An RFID transponder device generally operates as follows. The RFID transponder device is brought within reach of an RFID reader device. The RFID reader device broadcasts an RF signal which is received by an antenna of the RFID transponder device. The RF signal triggers the RFID transponder device to send a response using the same antenna, which on its turn is received by the RFID reader device. The response of the RFID tag may vary from application to application, but generally it comprises at least one of: a state indicator, a product identifier, and a serial number.
There exist many communication protocols for the communication between the RFID reader device and the RFID transponder. An example of such protocol is laid out in the ISO15693 standard, which hereby incorporated by reference in its entirety. Whatever protocol is used, it is important that the reader device determines what are the features of the RFID transponder device. Such features are generally determined by the RFID reader device in the first communication actions with the RFID transponder device. The RFID reader generally uses a look-up table (LUT) to obtain the information about the optional & custom feature set (based upon a tag identifier within the response). However, the RFID product portfolio in the market grows rapidly.
A problem of the known RFID transponder system is that with a broader and more dynamic RFID tag product portfolio the look-up table solution turns out to be not sufficiently flexible.